A controversial condo project next to the Brooklyn Bridge is sailing through the city’s land-use review process — and that has caught the attention of good government groups, who say the secret of its success may lie in the lobbying megabucks the developer doled out.

The project has a staunch opponent in local Councilman David Yassky, who says the Dock Street building in DUMBO is out of scale and too close to the bridge, forever destroying historic views of the iconic span. And that adversary, says Dick Dadey, executive director of the government watchdog group Citizens Union, “should have been enough to kill it a long time ago” because the council historically backs local council members on land-use issues.

But Dadey believes the developer’s lobbying effort has been too much to overcome.

Yassky (D-Brooklyn) will hold a rally today on the steps of City Hall with other project opponents. But Dadey says their pleas might not be heard over the mounds of cash developer Two Trees Management has thrown at council leaders.

The owners of the company, David and Jed Walentas, and their top staff have doled out $29,700 in campaign donations to Councilwoman Melinda Katz and another $19,800 to Council Speaker Christine Quinn, since the project was resubmitted in 2007, records show.

Katz, a Queens Democrat running for comptroller, heads the council real estate committee, where the project heads next month after previously being backed by the local community board, borough president and Planning Commission.

Both Katz and Quinn yesterday said donations never affect how they vote.

Parties are limited to donating up to $4,950 for a citywide campaign, but Dadey said this is a prime example of how firms can skirt the law by recruiting a number of employees to make donations on the company’s behalf.

Two Trees had a similar plan shot down in 2004, but in 2007 offered to include a public middle school and additional parking in the hopes of swaying community members and city officials.

The company spent $409,323 lobbying the city since Jan. 2007, with much of the money going towards trying to sway support for the Dock Street plan.